#include "stm32f0xx_hal.h"

#include "config.h"

#include "states.h"

#include "ssd1306.h"

#include "eeprom_min.h"

#include "gpio.h"

#include "spi.h"

#include "stringhelpers.h"

#include "display.h"

#include "usb_device.h"

#include "usbd_cdc_if.h"

// Prototypes

// Move to header file

void process();

void restore_settings();

void save_settings();

void save_setpoints();

void SystemClock_Config(void);

therm_settings_t set;

therm_status_t status;

// Globalish setting vars

SPI_HandleTypeDef hspi1;

static __IO uint32_t TimingDelay;

void deinit(void)

{

    HAL_DeInit();

}

volatile int i=0;

int main(void)

{

    /* Reset of all peripherals, Initializes the Flash interface and the Systick. */

    HAL_Init();

    /* Configure the system clock */

    SystemClock_Config();

    /* Unset bootloader option bytes (if set) */

    void bootloader_unset(void);

    /* Initialize all configured peripherals */

    init_gpio();

    MX_USB_DEVICE_Init();

    // USB startup delay

    HAL_Delay(1000);

    HAL_GPIO_WritePin(LED_POWER, 1);

    // TODO: Awesome pwm of power LED 

    // Configure 1ms SysTick (change if more temporal resolution needed) 

    //RCC_ClocksTypeDef RCC_Clocks;

    //RCC_GetClocksFreq(&RCC_Clocks);

    //SysTick_Config(RCC_Clocks.HCLK_Frequency / 1000);

    // Init SPI busses

    init_spi();

    // Init OLED over SPI

    ssd1306_Init();

    ssd1306_clearscreen();

    // Default settings 

    set.boottobrew = 0;

    set.temp_units = TEMP_UNITS_CELSIUS;

    set.windup_guard = 1;

    set.k_p = 1;

    set.k_i = 1;

    set.k_d = 1;

    set.ignore_tc_error = 0;

    set.setpoint_brew = 0;

    set.setpoint_steam = 0;

    // Default status

    status.temp = 0;

    status.temp_frac = 0;

    status.state_resume = 0;

    status.state = STATE_IDLE;

    status.setpoint = 0;

    status.pid_enabled = 0;

    // Load settings (if any) from EEPROM

    restore_settings();

    if(set.boottobrew)

      status.state = STATE_PREHEAT_BREW; // Go to brew instead of idle if configured thusly

    // Startup screen 

    ssd1306_DrawString("protofusion.org/therm", 3, 0);

    HAL_Delay(1500);

    ssd1306_clearscreen();

    // Main loop

    while(1)

    {

        // Process sensor inputs

        process();

        // Run state machine

        display_process(&set, &status); 

    }

}

/** System Clock Configuration

*/

void SystemClock_Config(void)

{

  RCC_OscInitTypeDef RCC_OscInitStruct;

  RCC_ClkInitTypeDef RCC_ClkInitStruct;

  RCC_PeriphCLKInitTypeDef PeriphClkInit;

  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI48;

  RCC_OscInitStruct.HSI48State = RCC_HSI48_ON;

  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;

  HAL_RCC_OscConfig(&RCC_OscInitStruct);

  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_SYSCLK;

  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI48;

  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;

  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

  HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1);

  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_USB;

  PeriphClkInit.UsbClockSelection = RCC_USBCLKSOURCE_HSI48;

  HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

  __SYSCFG_CLK_ENABLE();

}

void update_temp() {

    // Assert CS

    HAL_GPIO_WritePin(MAX_CS, 0);

    uint8_t rxdatah[1] = {0x00};

    uint8_t rxdatal[1] = {0x00};

    HAL_SPI_Receive(&hspi1, rxdatah, 1, 100);

    HAL_SPI_Receive(&hspi1, rxdatal, 1, 100);

    // Release CS

    HAL_GPIO_WritePin(MAX_CS, 1);

    // Assemble data array into one var

    uint16_t temp_pre = rxdatal[0] | (rxdatah[0]<<8);

    if(temp_pre & 0b0000000000000010) {

        ssd1306_clearscreen();

        HAL_Delay(100); // FIXME: remove?

        status.tc_errno = 4;

        status.state = STATE_TC_ERROR;

        status.temp = 0;

        status.temp_frac = 0;

    }

    else if(temp_pre & 0b0000000000000001 && !set.ignore_tc_error) {

        status.tc_errno = 1;

        HAL_Delay(100); // FIXME: remove?

        status.state_resume = status.state;

        status.state = STATE_TC_ERROR;

        status.temp = 0;

        status.temp_frac = 0;

    }

    else 

    {

        if(status.state == STATE_TC_ERROR)

        {

            status.state = status.state_resume;

            ssd1306_clearscreen();

        }

        uint8_t sign = status.temp >> 15;// top bit is sign

        temp_pre = temp_pre >> 2; // Drop 2 lowest bits

        status.temp_frac = temp_pre & 0b11; // get fractional part

        status.temp_frac *= 25; // each bit is .25 a degree, up to fixed point

        temp_pre = temp_pre >> 2; // Drop 2 fractional bits 

        int8_t signint;

        if(sign) {

            signint = -1;

        }

        else {

            signint = 1;

        }

        // Convert to Fahrenheit

        if(set.temp_units == TEMP_UNITS_FAHRENHEIT)

        {

            status.temp = signint * ((temp_pre*100) + status.temp_frac);

            status.temp = status.temp * 1.8;

            status.temp += 3200;

            status.temp_frac = status.temp % 100;

            status.temp /= 100;

            status.temp += set.temp_offset;

        }

        // Use Celsius values

        else

        {

            status.temp = temp_pre * signint;

            status.temp += set.temp_offset;

        }

    }

}

// PID implementation

// TODO: Make struct that has the last_temp and i_state in it, pass by ref. Make struct that has other input values maybe.

int16_t last_pid_temp = 0;

uint8_t last_pid_temp_frac = 0;

int16_t i_state = 0;

int16_t update_pid(uint16_t k_p, uint16_t k_i, uint16_t k_d, int16_t temp, uint8_t temp_frac, int16_t setpoint) 

{

  // Calculate instantaneous error

  int16_t error = (int16_t)setpoint - (int16_t)temp; // TODO: Use fixed point fraction

  // Proportional component

  int16_t p_term = k_p * error;

  // Error accumulator (integrator)

  i_state += error;

  // to prevent the iTerm getting huge despite lots of 

  //  error, we use a "windup guard" 

  // (this happens when the machine is first turned on and

  // it cant help be cold despite its best efforts)

  // not necessary, but this makes windup guard values 

  // relative to the current iGain

  int16_t windup_guard_res = set.windup_guard / k_i;  

  // Calculate integral term with windup guard 

  if (i_state > windup_guard_res) 

    i_state = windup_guard_res;

  else if (i_state < -windup_guard_res) 

    i_state = -windup_guard_res;

  int16_t i_term = k_i * i_state;

  // Calculate differential term (slope since last iteration)

  int16_t d_term = (k_d * (status.temp - last_pid_temp));

  // Save temperature for next iteration

  last_pid_temp = status.temp;

  last_pid_temp_frac = status.temp_frac;

  int16_t result = p_term + i_term - d_term;

  // Put out tenths of percent, 0-1000. 

  if(result > 1000)

    result = 1000;

  else if(result < -1000)

    result = -1000;

  // Return feedback

  return result;

}

uint32_t last_ssr_on = 0;

uint32_t last_vcp_tx = 0;

uint32_t last_led = 0;

int16_t ssr_output = 0; // Duty cycle of ssr, 0 to SSR_PERIOD 

// Process things

void process()

{

    update_temp(); // Read MAX31855

    // TODO: Add calibration offset (linear)

    uint32_t ticks = HAL_GetTick();

    if(ticks - last_led > 400) 

    {